Welding Safety

AWS SAFETY AND HEALTHFACT SHEET BUNDLE

FOR CHEMICAL INDUSTRY WELDING

The following safety fact sheets and the complete 66-page ANSI Z49.1 Safety in Welding, Cutting, and Allied Processes are available for free download at www.aws.org/safety:

1: Fumes and Gases 2: Radiation 3: Noise 4: Chromium and Nickel in Welding Fume 5: Electrical Hazards 6: Fire and Explosion Prevention 7: Burn Protection 8: Mechanical Hazards 9: Tripping and Falling 10: Falling Objects 11: Confined Spaces 12: Contact Lens Wear 13: Ergonomics in the Welding Environment 14: Graphic Symbols for Precautionary Labels 15: Style Guidelines for Safety and Health Documents 16: Pacemakers and Welding 17: Electric and Magnetic Fields (EMF) 18: Lockout/Tagout 19: Laser Welding and Cutting Safety 20: Thermal Spraying Safety 21: Resistance Spot Welding

22: Cadmium Exposure from Welding & Allied Processes 23: California Proposition 65 24: Fluxes for Arc Welding and Brazing: Safe Handling and Use 25: Metal Fume Fever 26: Arc Viewing Distance 27: Thoriated Tungsten Electrodes 28: Oxyfuel Safety: Check Valves and Flashback Arrestors 29: Grounding of Portable and Vehicle Mounted Welding Generators 30: Cylinders: Safe Storage, Handling, and Use 31: Eye and Face Protection for Welding and Cutting Operations 33: Personal Protective Equipment (PPE) for Welding & Cutting 34: Coated Steels: Welding and Cutting Safety Concerns 36: Ventilation for Welding & Cutting 37: Selecting Gloves for Welding & CuttingZ49.1: Safety in Welding, Cutting, and Allied Processes

Fact Sheet 4: Chromium and Nickel in Welding Fume

Fact Sheet 11: Confined Spaces Fact Sheet 24: Fluxes for Arc Welding

and Brazing: Safe Handling and Use Fact Sheet 27: Thoriated Tungsten

Electrodes Fact Sheet 36: Ventilation for Welding &

Cutting

Includes the following concise and helpful fact sheets from the American Welding

Society’s Committee on Safety and Health

www.aws.org/safety

Safety and Health Fact Sheet No. 4 October 2003 © 2003 American Welding Society

Chromium and Nickel in Welding Fume

AWS disclaims liability for any injury to persons or to property, or other damages of any nature whatsoever, whether special, indirect, consequential or compensatory, directly or indirectly resulting from the publication, use of, or reliance on this Safety and Health Fact Sheet. AWS also makes no guaranty or warranty as to the accuracy or completeness of any information published herein. Fact Sheet No. 4 — 10/03 Page 1

INTRODUCTION The fume from welding processes may contain compounds of chromium, including hexavalent chromium, and of nickel. The composition of the base metals, the welding materials used, and the welding processes affect the specific compounds and concentrations found in the welding fume. IMMEDIATE EFFECTS OF OVER-EXPOSURE TO FUMES CONTAINING CHROMIUM AND NICKEL • Similar to the effects produced by

fumes from other metals. • Cause symptoms such as nausea,

headaches, dizziness, and respiratory irritation.

• Some persons may develop a

sensitivity to chromium or nickel which can result in dermatitis or skin rash.

CHRONIC (LONG TERM) EFFECTS OF EXPOSURE TO FUMES CONTAINING CHROMIUM AND NICKEL • Definite effects are not yet determined • Conclusions from the National Institute

for Occupational Safety and Health (NIOSH): some forms of hexavalent chromium and nickel and their inorganic compounds should be considered occupational carcinogens (cancer-causing agents).

• NIOSH Criteria Documents 76–129 and

77–164 (listed below) contain these conclusions based on data from the chromate producing industry and from nickel ore-refining processes.

• Conclusions from the International

Agency for Research on Cancer (IARC): (1) there is limited evidence in humans for the carcinogenicity of welding fumes and gases, and (2) there is inadequate evidence in experimental animals for the carcinogenicity of welding fumes.

OVERALL EVALUATION • Welding fumes are possibly

carcinogenic to humans (Group 2B). • No determination has yet been made

concerning the health effects on welders or users of chromium- or nickel-containing alloys.

• Nevertheless, give consideration to the

NIOSH and IARC conclusions. HOW TO PROTECT AGAINST OVER-EXPOSURE • Do not breathe fumes and gases. Keep

your head out of the fumes. • Use enough ventilation or exhaust at

the arc or both to keep fumes and gases from your breathing zone and general area.


• If ventilation is questionable, use air sampling to determine the need for corrective measures.

• Keep exposure as low as possible. INFORMATION SOURCES National Institute for Occupational Safety and Health (NIOSH). Criteria for a Recommended Standard: Occupational Exposure to Chromium (VI), NIOSH Publication No. 76-129. Cincinnati, OH (telephone: 800-356-4674; web site: http://www.cdc.gov/niosh/homepage.html). National Institute for Occupational Safety and Health (NIOSH). Criteria for a Recommended Standard: Occupational Exposure to Inorganic Nickel, NIOSH Publication No. 77-164. Cincinnati, OH (telephone: 800-356-4674; web site: http://www.cdc.gov/niosh/homepage.html). American Welding Society (AWS). Fumes and Gases in the Welding Environment, published by the American Welding Society, 550 NW LeJeune Road, Miami, FL 33126; telephone 800-443-9353; Web site: www.aws.org. American Conference of Governmental Industrial Hygienists (ACGIH). Threshold Limit Values for Chemical Substances and Physical Agents and Biological Exposure Indices, available from ACGIH, 1330 Kemper Meadow Drive, Cincinnati, OH 45240-1634 (telephone: 513-742-2020; web site: www.acgih.org). Occupational Safety and Health Administration (OSHA). Code of Federal Regulations, Title 29 Labor, Parts 1910.1 to 1910.1450, available from the U.S. Government Printing Office, Superintendent of Documents, P.O. Box 371954, Pittsburgh, PA 15250-7954

(telephone: 800-321-6742; web site: www.osha.gov). American Conference of Governmental Industrial Hygienists (ACGIH). Documentation of the Threshold Limit Values and Biological Exposure Indices, available from ACGIH, 1330 Kemper Meadow Drive, Cincinnati, OH 45240-1634 (telephone: 513-742-2020; web site: www.acgih.org). IARC Monographs on the Evaluation of Carcinogenic Risks to Humans, Chromium, Nickel, and Welding, Vol. 49 (1990), Oxford University Press, New York, NY 10016 (telephone: 212-726-6000; web site: www.oup-usa.org). The following references include the specific precautionary methods used to protect against exposure to fumes and gases: American National Standards Institute (ANSI). Safety in Welding, Cutting, and Allied Processes (ANSI Z49.1), published by the American Welding Society, 550 NW LeJeune Road, Miami, FL 33126; telephone 800-443-9353; Web site: www.aws.org. National Institute for Occupational Safety and Health (NIOSH). Safety and Health in Arc Welding and Gas Welding and Cutting, NIOSH Publication No. 78-138. Cincinnati,OH (telephone: 800-356-4674; web site: http://www.cdc.gov/niosh). Mine Safety and Health Administration (MSHA). Code of Federal Regulations, Title 30 Mineral Resources, Parts 1 to 199, available from the U.S. Government Printing Office, Superintendent of Documents, P.O. Box 371954, Pittsburgh, PA 15250-7954 (telephone: 202-693-9400; web site: www.msha.gov).

Safety and Health Fact Sheet No. 11 September 2009 © 2009 American Welding Society

Hot Work in Confined Spaces


NATURE OF THE HAZARD Many different places require welding, cutting, and other hot work. Some of these places lack room and become “confined spaces.” Confined spaces have the following characteristics: • Limited space, entry, or exit. • Poor ventilation – lack of safe breathing

air and possible buildup of hazardous gases, fumes, and particles.

EXAMPLES OF CONFINED SPACES Small rooms Process vessels Pits Tunnels Vats Furnaces Storage tanks Pipelines Sewers Silos Degreasers Boilers Reactor vessels Utility vaults Compartments of ships Ventilation ducts Unventilated room areas Conveyers REASONS FOR DEATHS AND SERIOUS INJURIES FROM HOT WORK IN CONFINED SPACES • Fire • Electric shock • Exposure to hazardous air contaminants • Explosion • Asphyxiation

ACTIONS REQUIRED BEFORE APPROVING HOT WORK IN A CONFINED SPACE • Determine if special training or a permit

is required to enter the space. • Open all covers and secure them from

closing. • Test atmosphere for:

(1) suitable oxygen content (2) combustibles or reactives (3) toxics

Note: The testing requires special equipment and training.

• Isolate lines by capping or double

blocking and bleeding. Keep vents open and valves leak-free.

• Lock out/tagout all systems not required

during hot work. • Provide means for readily turning off

power, gas, and other supplies from outside the confined space.

• Protect or remove any hazardous

materials or materials which may become hazardous when exposed to hot work.


REQUIRED ACTIONS DURING HOT WORK IN A CONFINED SPACE • Continuously ventilate and monitor air to

ensure fumes and gases do not exceed safe exposure limits.

• 29 CFR 1910.252(c) and 1926.353(c)

require the use of local exhaust ventilation or supplied air respiratory protection when hot work is performed in a confined space where there is a potential for exposure to fluorine compounds (fluxes and rod coatings), zinc, lead, cadmium, or mercury. When beryllium is present, use both local exhaust and a supplied-air respirator.

• 29 CFR 1926.353(c) requires the use of

local exhaust ventilation or supplied air respiratory protection when hot work is performed in a confined space where there is a potential for exposure to chromium or when Gas Metal Arc Welding is performed on stainless steel.

• Use NIOSH/MSHA (National Institute for

Occupational Safety and Health/Mine Safety and Health Administration) approved breathing device when required by code.

• Keep unnecessary persons and

equipment out of, and away from, the confined space.

• Do not allow equipment to block exit or

rescue efforts. • Place as much equipment as possible

outside the confined space. • Do not enter a confined space unless a

watchperson, properly equipped and trained for rescue, is outside. Maintain continuous communications with the worker inside.

• When possible, provide means for

readily turning off power, gases, and fuel from inside the confined space, even if outside turn-off means are provided.

INFORMATION SOURCES American National Standards Institute (ANSI). Safety in Welding, Cutting, and Allied Processes (ANSI Z49.1), published by the American Welding Society, 550 NW LeJeune Road, Miami, FL 33126; telephone 800-443-9353; web site: www.aws.org. Occupational Safety and Health Administration (OSHA). Code of Federal Regulations, Title 29 Labor, Parts 1910 and 1926, available from the U.S. Government Printing Office, 732 North Capitol Street NW, Washington, DC 20401; telephone: 800-321-6742; web site: www.osha.gov. Mine Safety and Health Administration (MSHA). Code of Federal Regulations Title 30 Mineral Resources, Parts 1 to 199, available from the U.S. Government Printing Office, 732 North Capitol Street NW, Washington, DC 20401; telephone: 202-693-9400; web site: www.msha.gov. American National Standards Institute (ANSI). Safety Requirements for Confined Spaces (ANSI Z117.1), available from ANSI, 25 West 43rd Street, New York, NY 10036; telephone: 212-642-4900; web site: www.ansi.org. National Institute for Occupational Safety and Health (NIOSH) Respirator Rule. Code of Federal Regulations, Title 42 Public Health, Part 84, available from the U.S. Government Printing Office, 732 North Capitol Street NW, Washington, DC 20401; telephone: 800-356-4674; web site: www.cdc.gov/niosh.

Fact Sheet No. 24 January 2002 2002 American Welding Society

Safety and Health

Page 1Fact Sheet No. 24 – 1/02

FLUXES FOR ARC WELDING ANDBRAZING: SAFE HANDLING AND USE

INTRODUCTION

Fluxes are used in various arc weldingprocesses, such as Submerged–Arc Weld-ing (SAW) and Electroslag Welding (ESW).Fluxes are also used in most brazingapplications. Fluxes are available in variousforms such as granules, powder, paste, orliquid. There are hazards when dealing withfluxes.

HAZARD OVERVIEW

The possible hazards associated withhandling and using fluxes include thefollowing:

• Inhaling toxic or corrosive flux dust

• Breathing welding fumes and gases

• Getting flux on the skin and in the eyes

• Swallowing toxic or corrosive flux or dust

• Breathing and swallowing flux particlesduring recovering and grinding.

The makeup and amount of these hazardousmaterials varies depending on the flux andthe process. Individuals with pre-existingphysical conditions, such as allergies or lungdiseases, may react to levels belowallowable exposure limits and havesymptoms that normal, healthy adults do notexperience.

ACUTE (SHORT TERM) EFFECTS OFOVEREXPOSURE

Overexposure to flux may cause thefollowing symptoms:

• General overexposure may cause irrita-tion, burning, and bleeding of the exposed

tissue, headache, dizziness, and short-ness of breath.

• Dust, fumes and gases may irritate theskin, eyes, and respiratory system.

• Toxic, corrosive, or oxygen–depletinggases can cause fluid in the lungs,suffication, and death.

• Fumes containing chromium or nickelcompounds may irritate the skin andrespiration tract and cause Metal FumeFever (see Fact Sheet Number 25).

• Flux products containing both fluoride andhydrogen compounds may produce corro-sive and toxic hydrofluoric acid which cancause irritation to skin, eyes, and the noseand throat.

• Swallowing or breathing barium oxide dustor fume can result in abdominal pain,vomiting, paralysis, and death.

CHRONIC (LONG TERM) EFFECTS OFOVEREXPOSURE

Long term overexposure to inhalable weld-ing fumes may lead to their accumulation inthe body. The effect is cumulative, depend-ing on concentration and time of exposure.The accumulation, evident from x-rayexamination, may or may not result inreduced lung function or disease. Smokingor other non-welding exposure to hazardousparticules may cause or aggravate this typeof lung accumulation condition. Chronicfluoride absorption can cause calcium lossfrom the bones and can discolor or spot theteeth. Prolonged exposure to manganeseoxides may affect the central nervoussystem, causing tiredness, fatigue, sleepi-ness, muscular weakness, emotional distur-bances, and uncontrolled movements while

Fact Sheet No. 24 – 1/02

walking (muscle spasms). Chronic overex-posure to respirable crystalline silica mayresult in silicosis, a disabling lung disease,and also a suspected carcinogen to thelungs. Nickel and chromium VI compounds,when present, and when inhaled over longperiods, are carcinogenic. Nickel fumes mayalso cause fibrous masses and fluid in thelungs.

OVERALL EVALUATION OF POTENTIALHAZARDS

Fluxes are safe and useful when handledand used properly and when recommendedsafety procedures are followed. The majorhazards to avoid are overexposure bybreathing, swallowing, or inhaling the dust orfumes and gases, especially those contain-ing respirable crystalline silica and fluorides.If the application recovers used flux, as iscommon in Submerged–Arc Welding (SAW),and then reuses or grinds the flux for reuse,overexposure to dust happens quickly ifprecautions are not taken.

Some submerged arc welding fluxes maycontain very small quantities of naturallyoccurring radioactive material (NORM). Fluxmaterials containing sufficiently low con-centrations of NORM are not subject tofederal radiation control regulations. Thesefluxes do not present an environmental orhealth hazard. Contact the flux manufacturerfor further information.

HOW TO PROTECT AGAINST OVEREXPO-SURE

• Wear proper hand, face, and bodyprotection when handling or when other-wise exposed to fluxes and their dust,fumes and gases––this means protective(leather, rubber) gloves, goggles, and fullclothing with long sleeves and long pants(not shorts).

• Avoid breathing the dust or fumes andgases. Keep your head out of the fumes,dust, and gases. Use enough ventilation,

exhaust at the arc, or both, to keep fumes,dust, and gases from your breathing zoneand the general area. When necessary,wear an approved mask or respirator.

• Do not consume food or beverages inareas where flux dust or fumes or gasesmay be generated or may be present.

• During brazing, do not overheat the fluxes.Follow the manufacturer’s recommendedprocedures. Overheating results in thegeneration of, and potential exposure to,excessive fumes and gases.

INFORMATION SOURCESAmerican Welding Society (AWS) Study.Fumes and Gases in the Welding Environ-ment and other Safety and Health publica-tions, available from American WeldingSociety, 550 N.W. LeJeune Road, Miami, FL33126.

Occupational Safety and Health Administra-tion (OSHA). Code Of Federal Regulations,Title 29 Labor, Chapter XVII, Parts 1901.1 to1910.1450, Order No. 869-019-00111-5,available from Superintendent of Docu-ments, U.S. Government Printing Office,P.O. Box 371954, Pittsburgh, PA 15250.

American Conference of GovernmentalIndustrial Hygienists (ACGIH) publication,Threshold Limit Values (TLV ) for ChemicalSubstances and Physical Agents in theWorkroom Environment, available fromAmerican Conference of GovernmentalIndustrial Hygienists, 1330 Kemper MeadowDrive, Cincinnati, OH 45240.

American National Standards Institute(ANSI). Safety in Welding, Cutting, and AlliedProcesses, Z49.1, available from AmericanWelding Society, 550 N.W. LeJeune Road,Miami, FL 33126.

National Institute for Occupational Safetyand Health (NIOSH). Criteria For A Recom-mended STD – Welding, Brazing AndTherm, NIOSH Publication No. 88-110.Cincinnati, Ohio: National Institute forOccupational Safety and Health.

Fact Sheet No. 24 – 1/02

American Welding Society (AWS). SafetyAnd Health Fact Sheet No. 1, Fumes AndGases, available from American WeldingSociety, 550 N.W. LeJeune Road, Miami, FL33126.

American Welding Society (AWS). SafetyAnd Health Fact Sheet No. 25, Metal FumeFever, available from American WeldingSociety, 550 N.W. LeJeune Road, Miami, FL33126.

For specific information, refer to theapplicable Material Safety Data Sheet(MSDS) available from the manufacturer,distributor, or supplier of the specific flux.

American Welding Society (AWS). A Sam-pling Strategy Guide for Evaluating Contami-nants in the Welding Environment (AWSF1.3), available from American WeldingSociety, 550 N.W. LeJeune Road, Miami, FL33126.

TLV is a registered trademark of the ACGIH.

Safety and Health Fact Sheet No. 27 October 2003 © 2003 American Welding Society

Thoriated Tungsten Electrodes


INTRODUCTION Thoriated tungsten electrodes contain thorium, a radioactive material that can pose health and environmental risks at elevated exposure levels. Thorium is a low-level radioactive material that primarily emits alpha particles as well as some beta and gamma radiation. These electrodes are normally sharpened by grinding as part of the standard procedure while preparing to perform gas tungsten arc welding (GTAW). Dust particles from this grinding process can cause internal radiation exposure if the dust is accidentally ingested or inhaled, so caution is necessary. Concern regarding radiation exposure to the external body from these electrodes is minimal. Thoriated tungsten electrodes are widely used because they make good welds and are long lasting and quite easy to use. A thoriated tungsten electrode operates at a temperature well below its melting temperature compared to a pure tungsten electrode. This results in a much lower rate of consumption of the electrode during welding, which eliminates much of the “arc wander” associated with balled pure tungsten. Other reasons for their use include easier arc initiation, reduced weld metal contamination, higher current-carrying capacity, the ability to sharpen the electrode, and long life.

IS THERE A CONCERN TO THE USER? The risk of internal exposure during welding is negligible in most circumstances since the thoriated electrode is consumed at a very slow rate. During the grinding of the thoriated tungsten electrodes, radioactive dust is created, posing the potential hazard of internal radiation exposure by inhalation or ingestion unless care is taken to control the dust. HOW TO REDUCE EXPOSURE • Choose thorium-free tungsten

electrodes such as those containing cerium, lanthanum, yttrium, or zirconium whenever possible.

• Read, understand, and follow all

information in the Material Safety Data Sheet (MSDS) for the selected tungsten electrode.

• Use a high-efficiency dust collection

system to capture particles created during the grinding of electrodes or disturbed during housekeeping.

• Evaluate the ventilation system before

acceptance and periodically thereafter to minimize personnel and environmental contamination.


• Develop and implement standard operating procedures for the use of thoriated tungsten electrodes, including proper procedures for storage, grinding, use, housekeeping and disposal.

• Provide training in the operation of the

welding and grinding equipment, personal hygiene, and safety.

WHAT TO DO WITH THE COLLECTED DUST PARTICLES • Regularly remove the dust generated

by grinding. • Properly dispose of the dust and spent

electrodes in accordance with federal, state, and local regulations.

SUMMARY Several of the information sources listed indicate that the risk of occupational exposure to radiation during storage, handling, and welding with thoriated tungsten electrodes is negligible where simple precautions are taken. Special care should be taken to control and collect dust from grinding these electrodes in order to prevent a potential ingestion and inhalation exposure to radioactive dust particles resulting from this operation. INFORMATION SOURCES International Institute of Welding (IIW). Statement from Commission VIII, Health and Safety 2000. Welding with Non-Consumable Thoriated Tungsten Electrodes. Document IIW-VIII-1901-00. np: np.

Jankovic, J. T., W. S. Underwood, and G. M. Goodwin. 1999. Exposures from Thorium Contained in Thoriated Tungsten Electrodes. American Industrial Hygiene Journal 60: 384 – 389. Nuclear Regulatory Commission (NRC). Code of Federal Regulations, Title 10 Energy, Part 40.13 (c) (1) (iii) (Available from the U.S. Government Printing Office, Superintendent of Documents, P.O. Box 371954, Pittsburgh, PA 15250-7954; tel: 800-321-6742; Web site: www.nrc.gov). Oak Ridge National Laboratory (ORNL): Estimated Radiation Doses from Thorium and Daughters Contained in Thoriated Welding Electrodes, by L. M. McDowell-Boyer (ORNL/NUREG/TM-344). Oak Ridge, TN: ORNL, 1979. Sinclair, M. L., and K. S. Thind: “Assessment of Thorium Exposure Due to Grinding of Thoriated Tungsten Electrodes.” Paper presented at the American Industrial Hygiene Conference, Boston, MA., May 1992, Breslin, A. J., and W. B. Harris: Use of thoriated tungsten electrodes in inert gas shielded arc welding. Ind. Hyg. Q. 13:191-195 (1952). United States Nuclear Regulatory Commission. (February 1995). Airborne Thorium from Welding Rods. HPPOS-255 PDR-9308020142. U.S. NRC, Washington, DC. (Web site: www.nrc.gov).

Safety and Health Fact Sheet No. 36 September 2009 © 2009 American Welding Society

Ventilation for Welding and Cutting


INTRODUCTION Ventilation is used to control overexposures to the fumes and gases during welding and cutting. Adequate ventilation will keep the fumes and gases from the welder’s breathing zone. NOTE: This safety and health fact sheet does not address ventilation in confined spaces. Also, the term “welding” includes “cutting.”

NATURE OF THE HAZARD— THE FUME PLUME The heat of the arc or flame creates fumes and gases (fume plume). Fumes contain respirable particles. Gases include the shielding gas, and combustion products. The heat from the arc or flame causes the fume plume to rise. Fumes contain hazardous substances. Overexposure to them may cause acute (short term) or chronic (long term) health effects. Fumes and gases may be produced at toxic levels and they can displace oxygen in the air causing asphyxiation. Overexposure to welding fumes and gases can cause dizziness, illness, and even unconsciousness and death.

HOW TO AVOID THE HAZARD — VENTILATION Keep your head out of the fumes. Reposition the work, your head, or both to keep from breathing the fumes. Use ventilation to control the fumes and gases produced from cutting and welding. Adequate ventilation keeps exposures to airborne contaminants below allowable limits. Have a technically qualified person evaluate the exposure to determine if the ventilation is adequate. Wear an approved respirator when ventilation is not adequate or practical. Adequate ventilation depends on:

• Size and shape of the workplace

• Number and type of operations

• Contents of the fume plume

• Position of the worker’s and welder’s head

• Type and effectiveness of the ventilation

Adequate ventilation can be obtained through natural or mechanical means or both.


Natural Ventilation – is the movement of air through a workplace by natural forces. Roof vents, open doors and windows provide natural ventilation. The size and layout of the area/building can affect the amount of airflow in the welding area. Natural ventilation can be acceptable for welding operations if the contaminants are kept below the allowable limits.

Natural Ventilation: Using airflow from open windows, doors, and roof vents may be adequate.

Mechanical Ventilation – is the movement of air through a workplace by a mechanical device such as a fan. Mechanical Ventilation is reliable. It can be more effective than natural ventilation. Local exhaust, local forced air, and general ventilation are examples of mechanical ventilation. Local exhaust ventilation systems include a capture device, ducting and a fan. The capture devices remove fumes and gases at their source. Fixed or moveable capture devices are placed near or around the work. They can keep contaminants below allowable limits. One or more of the following capture devices are recommended:

• Vacuum nozzle at the arc

• Fume Hoods

• Gun mounted fume extractor

Some systems filter the airflow before exhausting it. Properly filtered airflow may be recirculated.

Local Exhaust Ventilation: Use enough local exhaust at the arc to remove the fumes and gases from your breathing area.

Local forced air ventilation is a local air moving system. A fan moves fresh air horizontally across the welder’s face. A wall fan is an example of Local Forced Air Ventilation. When using localized ventilation, remember:

• Locate the hood as close as possible to the work.

• Position the hood to draw the plume

away from the breathing zone.

• Curtains may be used to direct airflow.

• Some toxic materials or chemicals

may require increased airflows.

• Velocities above 100 feet per minute at the arc or flame may disturb the process or shielding gas.

• The capture device can depend on

the type of job. SUMMARY Adequate ventilation removes the fumes and gases from the welder’s breathing zone and general area. It prevents overexposure to contaminants. Approved respirators may be required when ventilation is not adequate.


To minimize worker overexposure to fumes and gases:

• Keep your head out of the fumes, and do not breathe the fumes.

• Reposition the work and your head

to avoid the fumes.

• Choose the correct ventilation method(s) for the specific operation.

• Use enough ventilation, exhaust at the arc, or both, to keep fumes and gases from your breathing zone and the general area.

• Understand what is in the fumes.

• Have a technically qualified person sample your breathing air and make recommendations.

• Keep hazardous air contaminants below allowable limits.

• Wear the proper respirator when necessary.

INFORMATION SOURCES American National Standards Institute (ANSI). Safety in Welding, Cutting, and Allied Processes (ANSI Z49.1), published by the American Welding Society, 550 NW LeJeune Road, Miami, FL 33126; telephone 800-443-9353; web site: www.aws.org. Occupational Safety and Health Administration (OSHA). Code of Federal Regulations, Title 29 Labor, Parts 1910.1 to 1910.1450, available from the U.S. Government Printing Office, 732 North Capitol Street NW, Washington, DC 20401; telephone: 800-321-6742; web site: www.osha.gov.

National Fire Protection Association (NFPA). Standard for Fire Prevention During Welding, Cutting, and Other Hot Work (NFPA 51B), available from National Fire Protection Association, 1 Batterymarch Park, P.O. Box 9101, Quincy, MA 02269–9101, telephone: 800–344–3555, web site: www.nfpa.org. American Conference of Governmental Industrial Hygienists (ACGIH), Industrial Ventilation – A Manual of Recommended Practice 21st edition, published by the ACGIH, 6500 Glenway Avenue, Building D-7, Cincinnati, OH 45211-4438; telephone , 513-742-2020; web site: www.acgih.org. American Welding Society (AWS). Ventilation Guide for Weld Fume (AWS F3.2), published by the American Welding Society, 550 NW LeJeune Road, Miami, FL 33126; telephone 800-443-9353; web site: www.aws.org. Edison Welding Institute (EWI). Reduction of Worker Exposure and Environmental Release of Welding Emissions (NSRP report No. 43149GTH, November 30, 2003), available from the Edison Welding Institute, 1250 Arthur E. Adams Drive, Columbus, OH 43221; telephone: 614-688-5000; web site: www.ewi.org. Occupational Safety and Health Administration (OSHA). OSHA Technical Manual (OTM), Section III Health Hazards, Chapter 3 Ventilation Investigation, available from OSHA, Room N3655, 200 Constitution Ave., N.W., Washington, DC 20210; telephone: 202-693-2095; web site: http://www.osha.gov.

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